Fig. 4. High-resolution analysis of Cep68 and Cep215 localisation. (A,B) U2OS cells were co-stained with antibodies against -tubulin (middle columns) and either Cep68 (A; left column) or Cep215 (B; left column) and examined using deconvolution on a Deltavision instrument. Right columns show merged images with Cep68 or Cep215 in green and -tubulin in red. Bars, 2 µm. (C) U2OS cells were subjected to pre-embedding immuno-gold labelling EM. Cells were labelled with anti-Cep68 (top left) or anti-Cep215 (bottom left) antibodies, followed by nanogold-coupled secondary antibody. Controls (right) show centrioles stained with secondary antibody only. Note that Cep68 decorates striking fibres protruding away from the proximal ends of centrioles; proximal ends are identified by the proximity of fibres to nascent pro-centrioles (white arrow) and their distance to distal appendages (white arrowhead). Bars, 250 nm.